31091-400-57 - Square D Coil

31091-400-57 - Square D Coil

When a coil goes bad, it doesn’t just slow things down—it can bring your whole system to a stop. The 31091-400-57 replacement coil is a simple, practical fix that gets your equipment back in service without replacing the entire contactor or starter.

This coil is designed for NEMA Size 4 devices and is commonly used with 8502SF contactors, 8536SF starters, and 8903SV lighting contactors. If you're working with any of these, this is a direct-fit solution that saves time and avoids unnecessary hassle. It’s rated for 440/480V AC at 50/60 Hz, so it works across standard industrial control voltages.

One thing you’ll notice right away is the build quality. The coil is fully encapsulated, which helps protect it from dust, moisture, and general wear you’d expect in real-world environments. That added protection goes a long way toward extending the life of the component and keeping your system reliable.

From a performance standpoint, it delivers the power you need to engage properly, with strong inrush capability and steady sealed consumption once it’s running. And when it comes time to install, the screw clamp terminals make the job straightforward—no complicated setup, just a secure connection and you’re good to go.

Whether you’re replacing a failed coil or keeping a spare on hand for maintenance, this is one of those parts that just makes sense to have ready.

Key Features and Benefits

• Direct replacement for worn or failed coils
• Fits 8502SF contactors, 8536SF starters, and 8903SV lighting contactors
• Rated for 440/480 VAC, 50/60 Hz
• Fully encapsulated to help protect against dirt and moisture
• Reliable inrush power for consistent operation
• Efficient power use during normal operation
• Screw clamp connections for quick installation
• Helps extend the life of existing equipment

Technical Specifications

• Catalog Number: 31091-400-57
• Product Type: Coil
• NEMA Size: 4
• Voltage Rating:480V AC @ 60 Hz
  440V AC @ 50 Hz
• Inrush Power: 1185–1260 VA
• Average Consumption: 85–89 VA
• Dimensions:
  • Height: approx. 2.9 in
  • Width: approx. 2.6 in
  • Depth: approx. 2.5 in
• Connection Type: Screw Clamp
• Construction: Encapsulated

Material Compliance and Certifications

• Built to meet standard industrial control requirements
• Suitable for commercial and industrial electrical systems
• Country of Origin: Mexico
• Manufacturer warranty: 18 months

Where It Works Best

• Motor control systems in industrial settings
• Commercial lighting control applications
• Maintenance and repair jobs where downtime matters
• Retrofit situations requiring a voltage-specific coil
• Facilities maintaining NEMA Size 4 equipment